[vrama.gurubaran]

Originally Posted by aimiim2008

purchased two apples a mango and a banana and paid 20.prices a +ve integers how many combi's possible.

please give the formula approach for this problem

If a + b = k, the number of possible solutions for (a,b) is k-1 provided both a & b are do not take zero.
now consider this sum..
2a+m+b =20... v ve to consider for each possible value. max possible value of a is 9 as if it is 10, m& b ll become 0 which is impossible.. So for a=9, m+b= 2. number of Possible solutions for(m,b) is 1.
Similarly, for a = 8, m+b = 4 implies 3 possible ways.. like this it goes on until a =1..
So v have 1+3+5+ 7+.....+17..
IT equals (9/2)(1+17) =81..

[fungus]

can any one discuss question set 50-53 of di.. where articles p q r s t are given and we have to calculate their SP and cp....